Thiazole disazo dyestuffs



Patented Aug. 10, 1954 UNITED STATES- PATENT OFFICE THIAZOLE DISAZO DYE STUFFS Raymond Gunst, Binningen,

Switzerland, as-

signor to Ciba Limited, Basel, Switzerland, a

'No Drawing. Application February 2, 1953, Serial No. 334,711

Claims priority, application Switzerland August 25, 1949 7 Claims. (01. 260-146) This application is a continuation in part of my copending application Serial No. 180,697, filed August 21, 1950. The present invention is based on the observation that the disazo dyestuffs of the formula 5 COOH HO and the complex copper compounds thereof are very valuable dyestuffs. In the above Formula 1 R1 represents a benzene radical containing the In the Formula 2 R1 and R2 have the meaning already given and monoazo dyestuifs of this 35 compositon are known products. As examples there may be mentioned in this connection:

4 amino 4' hydroxy 1:1 azobenzene 3'- carboxylic acid, 4-amino-2-chloro-4'-hydroxy- 1:1-azobenzene-3-carboxylic acid, 4-amino-4'- 40 hydroxy-1:1'-azobenzene-3 :3-dicarboxylic acid, 4 amino 4' hydroxy 5' methyl 1 :1 azobenzene-3'-carboxylic acid, 4-amino-5-methoxy- 2 methyl 4' hydroxy 1:1' azobenzene 3'- carboxylic acid-5-sulfonic acid. v 45 The monoazo dyestufi 01 the Formula 3 can be obtained by coupling diazotized 5-nitro-2- aminobenzoic acid with 2-[4'-(8"-hydroxynaph- 2 thyl [2"] aminophenyD] 6 methylbenzthiazole-X:6"-disulfonic acid and reducing the nitro group to the -NH2 group. A method for the preparation of the 2-[4'-8"-hydroxynaphthyl [2"] aminophenyD] 6 methylbenz- N smH thiazole-X:6-disulionic acid corresponding to the formula (4) H0 N son:

0 a CH;

HOsS-z S is given in Example 1 below.

The condensation of the amino-monoazo dyestuffs of the Formulae 2 and 3 to form the asymmetrical urea derivatives by means of phosgene is advantageously conducted in an aqueous medium, preferably with the, addition of an acidbinding agent, for example, an alkali carbonate,

SOaH

alkali acetate or an alkali ortho-phosphate or pyrophosphate.

On account of their good substantivity the dyestufis obtainable according to the present invention are especially valuable for the dyeing of providing metal may be carried out in the customary manner known per se.

Treatment'with agents yielding copper in substance may be of advantage when the complex copper compounds possess sufiicient solubility for application in the dyebath. It is preferably carried out in an acid medium and with a quantity of the agent providin copper which corresponds to one gram atom of copper or only a slight excess over it per molecular proportion of dyestuff. The so obtained cupriferous dyestuffs correspond to the formula in which R1 and R2 have the meanings already given.

With regard to the formulae of the cupriferous dyestuffs it should be explained that these formulae undoubtedly represent the correct stoiohiometric quantities of copper and the correct position of the copper atom in the complex, but the distribution of the main and secondary valences in the complex union of the copper has not yet been established with certainty.

Also when the solubility is sufficient, but especially when the dyestuffs do not contain sufficient solubilizing groups so that their complex metal compounds are less suitable for dyeing, the treatment can be carried out with agents providingmeta l, especially copper, with advantage on the fiber or in one bath partly in the dyebath and partly on the fiber, as is described for example in U. S. Patent No. 2,148,659. In many cases also very valuable dyeings are obtained by working according to the process in which the dyeings produced with the metal-free dyestuffs are after-treated with such aqueous solutions as contain on the one hand basic formaldehyde condensation products from compounds containing in the molecule at least once the atom groupor, as in the case for example of cyanamide, are easily capable of conversion into such compounds, and on the other hand water-soluble metal compounds, especially complex copper compounds.

The dyeings obtainable with the new dyestuffs on cellulosic fibers are as a rule distinguished by good fastness to washing and primarily by very good fastness to light.

The following examples illustrate the invention, the parts and percentages being by weight unless otherwise stated and the relation between parts by weight and parts by volume being the same as that between the kilogram and the liter.

Example 1 18.2 parts of 5-nitro-2-aminobenzoic acid are diazotized in the known manner. Meanwhile 55 parts of 2-[4-(8"-hydroxynaphthyl-[2"]-aminophenyb] 6 methyl-benzthiazole-X:6"-disulfonic acid are dissolved in 200 parts of water with the addition of 50 parts of a per cent.

SOsH

a concentrated aqueous solution of 42 parts of crystalline sodium sulfide. Owing to the reac 'tion the temperature rises to 58 C. Heating for a further hour is carried out at 75 C. and then the whole is carefully acidified with hydrochloric acid and filtered. The aminoazo dyestufi formed is freed from sulfur residues by dissolving to a dilute aqueous solution in the presence of weal; alkali and separated with sodium chloride, filtered off and dried.

14.1 parts of the aminoazo dyestuif thus pro.- duced are dissolved in 2000 parts of water together with 6.4 parts of the sodium salt of 4-amino 4. hydroxy-l:l-azobenzene-3'-carhoxylic acid, to the solution '20 parts of sodium carbonate added and phosgene introduced at 30- C. with stirring until no free amino group can any longer be detected- The unsymmetrical urea formed, which. corresponds to the formula 00 OH 7 HO N son;

an NH COOH H0 bath aftercoppering process is filtered off, dissolved in aqueous solution alkaline with sodium carbonate and precipitated by means of sodium chloride in the form of the sodium salt. The new dyestuif forms a dark powder which dissolves in water with an olive color and dyes cotton by the single-bath or twoin brown-olive shades of good fastness to washing and light.

Similar dyestuifs are obtained when in the reaction with phosgene 4-amino-2-chloro-4'- hydroxy-l 1 -azobenzene-3 -carboxylic acid or i-amino c'-hydroxy-5-methy -l:1-azobenz ne- 3'-carboxylic acid or -amino-5-methoxy-2e methyl-4 -hydroxy-1 1 -azobenzene-3 -carboxylicacid 5.'-sul fonic acid is used instead of i-amino- 4 -hydroxy -1 1 -.azobenzene.-3 .-carboxylic acid. The so-obtained dyestufis correspond to the fol.- lowing formulae mesa-175 and The 2- [4'-(8"-hydroxynaphthyl- [2"] -aminophenyl) l -6-methyl-benzthiazole-X 6' -disulfonic acid used as starting material in this example can be produced as follows:

24.0 parts of 1.:'l-dihydroxynaphthalene-3- sulfonic acid are suspended in 500 parts of commercial sodium bisuliite solution. At 95 0., 46 parts of 2 4 (4' aminophenyl) 6 --methyl- Hooo I benzthiazole-X-sulfonic acid (obtained by sulfonation of 2 (4' aminophenyl) 6 methylbenzthiazole with fuming sulfuric acid) are introduced and the reaction mixture is maintained for 60 hours with stirring and reflux cooling at 95-97 C. After cooling, the condensation product which is difiicultly soluble in acid solution, is filtered "off. For-purification the filter residue is dissolved in the hot in a medium alkaline with sodium carbonate and freed from any insoluble residue by filtration. By addition of dilute hydrochloric acid the condensation product is precipitated as an orange-brown deposit. If desired the condensation product can be freed from sulfurous acid by heating the suspension, until the sulfurous acid has completely evaporated.

Example 2 10 parts of the unsymmetrical urea prepared according to Example 1 and corresponding to the formula COOH HO O HO O l HOaS are dissolved in 500 parts of hot water. This solution is acidified to Congo red reaction by the addition of sulfuric acid and 5 parts of crystallized copper sulfate, dissolved in 50 parts of water, are added. The mixture is well stirred COOH HO COOH HO and heated up to 90 C. and maintained at this temperature for an hour. The complex copper compound thus formed is filtered off and converted to its sodium salt by redissolving in aqueous alkaline solution with sodium carbonate and precipitating the new copper-containing dyestufi by means of sodium chloride. The resulting dyestuff of the formula NHOC\ CH forms a dark powder which dissolves in water with an olive coloration and dyes cotton darkolive shades of good fastness to washing and light.

What I claim is:

1. A disazo dyestuff selected from the group consisting of the compounds of the formula I v /N 80:11 HN C\ OH:

and their complex copper compounds, in which formula R1 represents a benzene radical containing the groups -N==N and -NH- in paraposition relatively to one another and R2 represents a benzene radical containing a hydroxyl group in para-position with respect to the azo group and a carboxylic acid group in orthoposition to the hydroxyl group.

2. A disazo dyestufi of the formula ..HOaS

HOaS

SOIH

in which R1 represents a benzene radical containing the groups N=N-- and --NI-I- in para-position relatively to one another and R2 represents a benzene radical containing a hydroxyl group in para-position with respect to the azo group and a carboxylic acid group in ortho-position to the hydroxyl group.

- SOsH eczema" 7 3. mcupriferous disazo dyestufi of the formula.

e0 o.-cu--o* in which R1. represents a benzene radicalcontaining the groups--N==N-- and --NH-.- inparaposition relatively toone another and R5 repre group in para-position with respect to theazo sents a; benzene radicaleontaining a. hydroxyl groupend a carboxylic acid' group in ortho-position to thehydi'oxyrgroup.

4. The disazo deystuff'ofthe formula" COOH HO 5. The'di'sazo dyestufi of theformul;

QOOH HQ 6: The disazo dyestufiof the formula m0 COOH 110 N some I Bo. N=NONH+EHNON=N HOG n00 c x HOaSf.

'7; The cupriferous disazo dyestufi of the formula v COOCu--0 No references cited. 

1. A DISAZO DYESTUFF SELECTED FROM THE GROUP CONSISTING OF THE COMPOUNDS OF THE FORMULA 